Maternal and Perinatal Outcomes of Twin Pregnancy in 23 Low- and Middle-Income Countries

Background

Twin pregnancies in low- and middle-income countries (LMICs) pose a high risk to mothers and newborns due to inherent biological risks and scarcity of health resources. We conducted a secondary analysis of the WHO Global Survey dataset to analyze maternal and perinatal outcomes in twin pregnancies and factors associated with perinatal morbidity and mortality in twins.

Methods

We examined maternal and neonatal characteristics in twin deliveries in 23 LMICs and conducted multi-level logistic regression to determine the association between twins and adverse maternal and perinatal outcomes.

Results

279,425 mothers gave birth to 276,187 (98.8%) singletons and 6,476 (1.2%) twins. Odds of severe adverse maternal outcomes (death, blood transfusion, ICU admission or hysterectomy) (AOR 1.85, 95% CI 1.60–2.14) and perinatal mortality (AOR 2.46, 95% CI 1.40–4.35) in twin pregnancies were higher, however early neonatal death (AOR 2.50, 95% CI 0.95–6.62) and stillbirth (AOR 1.22, 95% CI 0.58–2.57) did not reach significance. Amongst twins alone, maternal age <18, poor education and antenatal care, nulliparity, vaginal bleeding, non-cephalic presentations, birth weight discordance >15%, born second, preterm birth and low birthweight were associated with perinatal mortality. Marriage and caesarean section were protective.

Conclusions

Twin pregnancy is a significant risk factor for maternal and perinatal morbidity and mortality in low-resource settings; maternal risk and access to safe caesarean section may determine safest mode of delivery in LMICs. Improving obstetric care in twin pregnancies, particularly timely access to safe caesarean section, is required to reduce risk to mother and baby.     

Agrobacterium-mediated transformation of Guignardia citricarpa: An efficient tool to gene transfer and random mutagenesis

Guignardia citricarpa is the causal agent of Citrus Black Spot (CBS), an important disease in Citriculture. Due to the expressive value of this activity worldwide, especially in Brazil, understanding more about the functioning of this fungus is of utmost relevance, making possible the elucidation of its infection mechanisms, and providing tools to control CBS. This work describes for the first time an efficient and successful methodology for genetic transformation of G. citricarpa mycelia, which generated transformants expressing the gene encoding for the gfp (green fluorescent protein) and also their interaction with citrus plant. Mycelia of G. citricarpa were transformed via Agrobacterium tumefaciens, which carried the plasmid pFAT-gfp, contains the genes for hygromycin resistance (hph) as well as gfp. The optimization of the agrotransformation protocol was performed testing different conditions (type of membrane; inductor agent concentration [acetosyringone – AS] and cocultivation time). Results demonstrated that the best condition occurred with the utilization of cellulose's ester membrane; 200 μM of AS and 96 h as cocultivation time. High mitotic stability (82 %) was displayed by transformants using Polymerase Chain Reaction (PCR) technique to confirm the hph gene insertion. In addition, the presence of gfp was observed inside mycelia by epifluorescence optical microscopy. This technique easy visualization of the behaviour of the pathogen interacting with the plant for the first time, allowing future studies on the pathogenesis of this fungus. The establishment of a transformation method for G. citricarpa opens a range of possibilities and facilitates the study of insertional mutagenesis and genetic knockouts, in order to identify the most important genes involved in the pathogenesis mechanisms and plant–pathogen interaction.     

Morphological study for understanding the sexual pattern in ghost shrimp Callichirus major (Crustacea: Axiidea)

Callichirus major is a species of ghost shrimp that has burrowing habits, building underground galleries in the intertidal region of beaches. This study aimed to analyse some morphological parameters to verify its type of sexual pattern. A sample of 79 individuals, collected at the beach of Corujão, Espírito Santo, Brazil, was used. Data on the external morphology, presence of gonopores, carapace length (CL) and cheliped lengths (Lch) were obtained. In addition, the gonads were processed for histological analysis. The animals were divided into three categories: A, individuals with male characteristics; B, those presenting exclusively female characteristics; C, animals with characteristics of intersex, which presented supernumerary gonopores. Positive allometries were found for Lch versus CL only for category A, characterizing the group's marked heterochely. Histologically, it was possible to observe the presence of oocytes in category A and one case of male tissue in an intersex individual (category C). However, no genital ducts of both sexes were found in that individual. Callichirus major presents controversial sexual characters, which makes it difficult to understand the reproductive parameters and sexual pattern. However, maybe that species can develop a sexual system of hermaphroditism.     

Modular Control of Treadmill vs Overground Running

Motorized treadmills have been widely used in locomotion studies, although a debate remains concerning the extrapolation of results obtained from treadmill experiments to overground locomotion. Slight differences between treadmill (TRD) and overground running (OVG) kinematics and muscle activity have previously been reported. However, little is known about differences in the modular control of muscle activation in these two conditions. Therefore, we aimed at investigating differences between motor modules extracted from TRD and OVG by factorization of multi-muscle electromyographic (EMG) signals. Twelve healthy men ran on a treadmill and overground at their preferred speed while we recorded tibial acceleration and surface EMG from 11 ipsilateral lower limb muscles. We extracted motor modules representing relative weightings of synergistic muscle activations by non-negative matrix factorization from 20 consecutive gait cycles. Four motor modules were sufficient to accurately reconstruct the EMG signals in both TRD and OVG (average reconstruction quality = 92±3%). Furthermore, a good reconstruction quality (80±7%) was obtained also when muscle weightings of one condition (either OVG or TRD) were used to reconstruct the EMG data from the other condition. The peak amplitudes of activation signals showed a similar timing (pattern) across conditions. The magnitude of peak activation for the module related to initial contact was significantly greater for OVG, whereas peak activation for modules related to leg swing and preparation to landing were greater for TRD. We conclude that TRD and OVG share similar muscle weightings throughout motion. In addition, modular control for TRD and OVG is achieved with minimal temporal adjustments, which were dependent on the phase of the running cycle.     

Investigating the effects of point mutations on the affinity between the cyanobacterial lectin microvirin and high mannose-type glycans present on the HIV envelope glycoprotein

Human immunodeficiency virus (HIV) infections continue to exert an enormous impact on global human health. This led experts to emphasize the importance of new measures for preventing HIV infections, including the development of vaccines and novel drugs. In this context, a promising approach involves the use of lectins that can bind the surface envelope glycoprotein gp120 of HIV with high affinity, preventing viral entry. The cyanobacterial lectin microvirin (MVN) has been proposed as a candidate for development as a topical microbicide because of its ability to bind to high mannose-type glycans, potently inhibiting HIV-1 entry. Thus, the aim of this computational study was to investigate the effects of four point mutations (D53Q, D53E, D53K, and D53W) on the structure and affinity of MVN with di-mannose (MAN). Molecular dynamics simulations followed by binding free energy calculations using MM-GBSA were employed. The calculated binding free energy of ligand-receptor complexation of MVN with MAN was ?26.02 kcal mol^-1. We identified in the wild-type protein that residues I45, T59, and Q81 have a major contribution to the binding free energy of di-mannose. Among the investigated mutants, the most promising one was the D53W mutation, with a theoretical binding free energy value of ?29.16 kcal mol^-1. We suggest that this increased stability is due to the introduction of extra rigidity on the hinge region connecting two key structural elements of the MVN binding site.     

Barefoot Plantar Pressure Indicates Progressive Neurological Damage in Patients with Human T-Cell Lymphotropic Virus Type 1 Infection

Background

The human T-Cell Lymphotropic Virus Type 1 (HTLV-1) is a retrovirus associated with neurological alterations; individuals with HTLV-1 infection may develop HTLV-1 associated myelopathy / tropical spastic paraparesis (HAM/TSP). Frequent neurological complaints include foot numbness and leg weakness. In this study, we compared the distribution of the body weight on different areas of the foot in HTLV-1 patients with HAM/TSP, asymptomatic HTLV-1 patients, and healthy individuals.

Methodology

We studied 36 HTLV-1 infected patients, who were divided in two groups of 18 patients each based on whether or not they had been diagnosed with HAM/TSP, and 17 control subjects. The evaluation included an interview on the patient’s clinical history and examinations of the patient’s reflexes, foot skin tactile sensitivity, and risk of falling. The pressure distribution on different areas of the foot was measured with baropodometry, using a pressure platform, while the patients had their eyes open or closed.

Main Findings

The prevalence of neurological disturbances—altered reflexes and skin tactile sensitivity and increased risk of falling—was higher in HTLV-1 HAM/TSP patients than in HTLV-1 asymptomatic patients. The medium and maximum pressure values were higher in the forefoot than in the midfoot and hindfoot in both HTLV-1 groups. In addition, the pressure on the hindfoot was lower in HAM/TSP patients compared to control subjects.

Conclusions

The neurological disturbances associated with HTLV-1 infection gradually worsened from HTLV-1 asymptomatic patients to HAM/TSP patients. Baropodometry is a valuable tool to establish the extent of neurological damage in patients suffering from HTLV-1 infection.     

Surgical Stress Abrogates Pre-Existing Protective T Cell Mediated Anti-Tumor Immunity Leading to Postoperative Cancer Recurrence

Anti-tumor CD8⁺ T cells are a key determinant for overall survival in patients following surgical resection for solid malignancies. Using a mouse model of cancer vaccination (adenovirus expressing melanoma tumor-associated antigen (TAA)—dopachrome tautomerase (AdDCT) and resection resulting in major surgical stress (abdominal nephrectomy), we demonstrate that surgical stress results in a reduction in the number of CD8⁺ T cell that produce cytokines (IFNγ, TNFα, Granzyme B) in response to TAA. This effect is secondary to both reduced proliferation and impaired T cell function following antigen binding. In a prophylactic model, surgical stress completely abrogates tumor protection conferred by vaccination in the immediate postoperative period. In a clinically relevant surgical resection model, vaccinated mice undergoing a positive margin resection with surgical stress had decreased survival compared to mice with positive margin resection alone. Preoperative immunotherapy with IFNα significantly extends survival in surgically stressed mice. Importantly, myeloid derived suppressor cell (MDSC) population numbers and functional impairment of TAA-specific CD8⁺ T cell were altered in surgically stressed mice. Our observations suggest that cancer progression may result from surgery-induced suppression of tumor-specific CD8⁺ T cells. Preoperative immunotherapies aimed at targeting the prometastatic effects of cancer surgery will reduce recurrence and improve survival in cancer surgery patients.     

Phenotypic Features of Circulating Leukocytes from Non-human Primates Naturally Infected with Trypanosoma cruzi Resemble the Major Immunological Findings Observed in Human Chagas Disease

Background

Cynomolgus macaques (Macaca fascicularis) represent a feasible model for research on Chagas disease since natural T. cruzi infection in these primates leads to clinical outcomes similar to those observed in humans. However, it is still unknown whether these clinical similarities are accompanied by equivalent immunological characteristics in the two species. We have performed a detailed immunophenotypic analysis of circulating leukocytes together with systems biology approaches from 15 cynomolgus macaques naturally infected with T. cruzi (CH) presenting the chronic phase of Chagas disease to identify biomarkers that might be useful for clinical investigations.

Methods and Findings

Our data established that CH displayed increased expression of CD32⁺ and CD56⁺ in monocytes and enhanced frequency of NK Granzyme A⁺ cells as compared to non-infected controls (NI). Moreover, higher expression of CD54 and HLA-DR by T-cells, especially within the CD8⁺ subset, was the hallmark of CH. A high level of expression of Granzyme A and Perforin underscored the enhanced cytotoxicity-linked pattern of CD8⁺ T-lymphocytes from CH. Increased frequency of B-cells with up-regulated expression of Fc-γRII was also observed in CH. Complex and imbricate biomarker networks demonstrated that CH showed a shift towards cross-talk among cells of the adaptive immune system. Systems biology analysis further established monocytes and NK-cell phenotypes and the T-cell activation status, along with the Granzyme A expression by CD8⁺ T-cells, as the most reliable biomarkers of potential use for clinical applications.

Conclusions

Altogether, these findings demonstrated that the similarities in phenotypic features of circulating leukocytes observed in cynomolgus macaques and humans infected with T. cruzi further supports the use of these monkeys in preclinical toxicology and pharmacology studies applied to development and testing of new drugs for Chagas disease.     

The Burden of Provider-Initiated Preterm Birth and Associated Factors: Evidence from the Brazilian Multicenter Study on Preterm Birth (EMIP)

Background

About 15 million children are born under 37 weeks of gestation worldwide. Prematurity is the leading cause of neonatal deaths and short/long term morbidities, entailing consequences not only for the individual, but also their family, health agencies, facilities and all community. The provider-initiated preterm birth is currently one of the most important obstetric conditions related to preterm births, particularly in middle and high income countries, thus decreasing the need for therapeutic preterm birth is essential to reduce global prematurity. Therefore detailed knowledge on the factors associated with provider-initiated preterm birth is essential for the efforts to reduce preterm birth rates and its consequences. In this current analysis we aimed to assess the proportion of provider-initiated (pi-PTB) among preterm births in Brazil and identify associated factors.

Methods and Findings

This is an analysis of a multicenter cross-sectional study with a nested case-control component called Brazilian Multicenter Study on Preterm Birth (EMIP). EMIP was conducted in 20 referral obstetric hospitals located in the three most populated of the five Brazilian regions. We analysed data of women with pi-PTB, defined as childbirth occurring at less than 37 weeks, medically indicated for maternal/fetal compromise or both; and women with term birth, childbirth at or after 37 weeks. Maternal, sociodemographic, obstetric, prenatal care, delivery, and postnatal characteristics were assessed as possible factors associated with pi-PTB, compared to term births. The overall prevalence of preterm births was 12.3%. Of these, approximately one-third of cases were initiated by the provider. Hypertensive disorders, placental abruption, and diabetes were the main maternal conditions leading to pi-PTB. Caesarean section was the most common mode of delivery. Chronic hypertension (OR 7.47; 95%CI 4.02–13.88), preeclampsia/eclampsia/HELLP syndrome (OR 15.35; 6.57–35.88), multiple pregnancy (OR 12.49; 4.86–32.05), and chronic diabetes (OR 5.24; 2.68–10.25) were the most significant factors independently associated with pi-PTB.

Conclusions

pi-PTB is responsible for about one-third of all preterm births, requiring special attention. The decision-making process relative to the choice of provider-initiated birth is complex, and many factors should be elucidated to improve strategies for its prevention, including evidence-based guidelines on proper management of the corresponding clinical conditions.